Unmanned aerial vehicle and operations thereof

ABSTRACT

The present invention provides methods and apparatus for unmanned aerial vehicles (UAVs) with improved reliability. According to one aspect of the invention, interference experienced by onboard sensors from onboard electrical components is reduced. According to another aspect of the invention, user-configuration or assembly of electrical components is minimized to reduce user errors.

CROSS-REFERENCE

This application is a continuation of U.S. patent application Ser. No.15/012,006, filed Feb. 1, 2016, which is a continuation of U.S. patentapplication Ser. No. 14/954,427, filed Nov. 30, 2015, now U.S. Pat. No.9,284,049, issued Mar. 15, 2016, and of U.S. patent application Ser. No.14/947,923, filed Nov. 20, 2015, now U.S. Pat. No. 9,321,530, issuedApr. 26, 2016, which are continuations of U.S. patent application Ser.No. 14/836,344, filed Aug. 26, 2015, now U.S. Pat. No. 9,233,754, issuedon Jan. 12, 2016, which is a continuation of U.S. patent applicationSer. No. 14/515,357, filed Oct. 15, 2014, now U.S. Pat. No. 9,221,536,issued on Dec. 29, 2015, which is a continuation of U.S. patentapplication Ser. No. 14/092,653, filed Nov. 27, 2013, now U.S. Pat. No.9,016,617, issued on Apr. 28, 2015, which is a continuation-in-part ofInternational Application No. PCT/CN2013/087053, filed Nov. 13, 2013,which claims the benefit of Chinese Patent Application No.201220686731.2, filed Dec. 13, 2012, and Chinese Patent Application No.201220604396.7, filed Nov. 15, 2012, the disclosures of each of whichare incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

In recent years, unmanned aerial vehicles (UAVs) have been widely usedin various fields such as aerial photography, surveillance, scientificresearch, geological survey, and remote sensing. Typically, the UAVscarry onboard a variety of electrical components used to control variousaspects of the operation of the UAVs. At the same time, the UAVssometimes also need to carry one or more sensors for navigational,surveillance or remote sensing purposes. However, the operation of someof such sensors can be affected by interference from the electricalcomponents, thereby reducing the reliability of such UAVs.

Furthermore, assembly of the UAV and configuration/ calibration of thesensors are typically required for the UAVs to function properly. Whensuch assembly, configuration or calibration is performed by untrainedusers, user mis-configuration or assembly errors can lead to malfunctionor damage to the UAVs. Therefore, there is a need for a UAV withimproved reliability by addressing the above-mentioned problems.

SUMMARY OF THE INVENTION

Methods and apparatus for providing improved unmanned aerial vehicles(UAVs) are provided. According to an aspect of the present invention, anunmanned aerial vehicle (UAV) is provided. The UAV comprises a housingcomprising an outer surface and an inner surface that forms a cavity;one or more electrical components disposed inside the cavity and adaptedto control operation of the UAV; and a sensor located outside thehousing, operation of the sensor being susceptible to interferencecaused by the one or more electrical components.

According to another aspect of the present invention, an unmanned aerialvehicle (UAV) is provided. The UAV comprises one or more pre-configuredelectrical components that are pre-configured by a manufacturer prior touse of said UAV by a user, said one or more electrical componentsincluding at least a flight control module or an electronic speedcontrol (ESC) module; and a sensor located on said UAV at a positionseparate from said one or more pre-configured electrical components,operation of the sensor being susceptible to interference caused by theone or more pre-configured electrical components.

According to yet another aspect of the present invention, the presentinvention provides an unmanned aerial vehicle (UAV) comprising one ormore electrical components adapted to control operation of the UAV; anda sensor located on an extension member extending away from said one ormore electric components, operation of the sensor being susceptible tointerference caused by the one or more electrical components.

According to yet another aspect of the present invention, the presentinvention provides an unmanned aerial vehicle (UAV) comprising one ormore electrical components adapted to control operation of the UAV; anda sensor located at least 3 cm away and at most 0.5 m away from the oneor more electrical components, operation of the sensor being susceptibleto interference caused by the one or more electrical components.

According to still yet another aspect of the present invention, thepresent invention an unmanned aerial vehicle (UAV) is provided. The UAVcomprises one or more electrical components adapted to control operationof the UAV, the one or more electrical components including a GPSreceiver; and a sensor including at least a magnetometer located on saidUAV at a position separate from the one or more electrical components,operation of the magnetometer being susceptible to interference causedby the one or more electrical components.

In some embodiments, the sensor is located on an extension memberextending from the housing and away from the cavity. The extensionmember includes a support member adapted to support, in whole or inpart, weight of said UAV when said UAV is not airborne. The supportmember can include a landing stand. Alternatively, the sensor can belocated directly on the outer surface of the housing. The UAV cancomprise one or more rotors and the sensor can be located underneath theone or more rotors.

In some embodiments, the minimum distance between the sensor and the oneor more electrical components is at least about 3 centimeters. In someembodiments, the maximum distance between the sensor and the one or moreelectrical components is at most 0.5 meters.

In some embodiments, at least one of the electrical components ispre-configured, by a manufacturer of the UAV. The at least onepre-configured electrical component can be used to form an electric unitnecessary and sufficient for controlling operation of said UAV. Theelectrical unit can include at least one of a flight control module, GPSreceiver or electronic speed control (ESC) module.

In some embodiments, the sensor is adapted to measure magnetic fields.The sensor can include a magnetometer. The magnetometer can include acompass. In some embodiments, the interference can include magneticinterference or electromagnetic interference. In some embodiments, theone or more electrical components can include a GPS receiver or anactuator assembly comprising a rotor blade and an actuator configured toactuate the rotor blade. In some embodiments, the one or more electricalcomponents include at least three actuator assemblies.

In some embodiments, the housing comprises a conductive shieldingmaterial. The housing can comprise an upper housing member and a lowerhousing member that are removably coupled to form the cavity. Thehousing can comprise a central housing member connected to one or morebranch housing members, the central housing member forming a centralcavity and the one or more branch housing members forming correspondingone or more branch cavities. In some embodiments, at least one of theone or more electrical components is located inside the central cavity.The at least one electrical component located inside the central cavitycan include at least one of a power source, flight control module,inertial measurement unit (IMU), or GPS receiver. In some embodiments,at least one of the one or more electrical components is located insideone of the one or more branch cavities. The at least one electricalcomponent located inside one of the one or more branch cavities caninclude an electronic speed control (ESC) module or an actuator. In someembodiments, the one or more branch housing members respectivelycorrespond to one or more rotors of the UAV. At least one of the one ormore branch housing members can be removably connected to the centralhousing member.

According to another aspect of the present invention, a method isprovided for reducing interference experienced by a sensor susceptibleto the interference from one or more electrical components of anunmanned aerial vehicle (UAV). The method comprises providing a UAVdescribed herein, thereby reducing said interference.

According to another aspect of the present invention, a kit forassembling an unmanned aerial vehicle (UAV) is provided. The kitcomprises (a) one or more electrical components adapted to controloperation of the UAV, and/or one or more rotor blades of said UAV; and(b) instructions comprising information for a user of said UAV toassemble component(s) of (a) with a magnetometer, such that when the UAVis assembled, the UAV is characterized in that it comprises: (1) (i) ahousing comprising an outer surface and an inner surface that forms acavity, disposed inside the cavity, the one or more electric components,and (ii) the magnetometer is located outside the housing; or (2) (i) ahousing comprising an outer surface and an inner surface that forms acavity, disposed inside the cavity, the one or more electric components,and (ii) the magnetometer is located at least 3 cm away from the one ormore electrical components; or (3) (i) the one or more electricalcomponent adapted to control operation of the UAV, and/or one or morerotor blades of said UAV, and (ii) a magnetometer located at least 3 cmaway and at most 0.5 m away from the one or more electrical components.

According to another aspect of the present invention, the presentinvention provides an alternative kit for assembling an unmanned aerialvehicle is provided. The kit comprises (a) magnetometer; and (b)instructions comprising information for a user of said UAV to assemblesaid magnetometer with one or more electrical components adapted tocontrol operation of the UAV, such that when the UAV is assembled, theUAV is characterized in that it comprises (1) (i) a housing comprisingan outer surface and an inner surface that forms a cavity, disposedinside the cavity, the one or more electric components, and (ii) themagnetometer is located outside the housing; or (2) (i) a housingcomprising an outer surface and an inner surface that forms a cavity,disposed inside the cavity, the one or more electric component, and (ii)the magnetometer is located at least 3 cm away from the one or moreelectrical component; or (3) (i) the one or more electrical componentadapted to control operation of the UAV, and/or one or more rotor bladesof said UAV, and (ii) a magnetometer located at least 3 cm away and atmost 0.5 m away from the one or more electrical components.

According to another aspect of the present invention, the presentinvention provides a kit for assembling an unmanned aerial vehicle, thekit comprising (a) a housing comprising an outer surface and an innersurface that forms a cavity; (b) one or more pre-configured electricalcomponents disposed inside the cavity and adapted to control operationof the UAV; (c) a magnetometer, operation of the magnetometer beingsusceptible to interference caused by the one or more electricalcomponents; and (d) instructions for assembling said UAV, such that whenthe UAV is assembled according to the instructions, the assembled UAV ischaracterized in that: (1) the magnetometer is located outside thehousing; or (2) the magnetometer is located at least 3 cm away from theone or more electrical component; or (3) the magnetometer is located atmost 0.5 m away from the one or more electrical components.

In some embodiments, the kit further comprises a housing comprising anouter surface and an inner surface that forms a cavity and wherein theone or more electrical components are located inside the cavity. In someembodiments, the kit further comprises a housing comprising an outersurface and an inner surface that forms a cavity and wherein themagnetometer is located inside the cavity.

In some embodiments, the kit further comprises an extension memberattachable to the housing and wherein the assembled UAV is furthercharacterized in that: the extension member is attached to the outersurface of the housing and extending away from the cavity and themagnetometer is located on the extension member.

According to another aspect of the present invention, a method ofassembling an unmanned aerial vehicle (UAV) is provided. The methodcomprises following instructions provided in a kit comprising one ormore electrical components adapted to control operation of the UAV,and/or one or more rotor blades of said UAV, thereby assembling saidUAV, wherein said UAV when assembled is characterized in that itcomprises: (1) (i) a housing comprising an outer surface and an innersurface that forms a cavity, disposed inside the cavity, the one or moreelectric components, and (ii) the magnetometer is located outside thehousing; or (2) (i) a housing comprising an outer surface and an innersurface that forms a cavity, disposed inside the cavity, the one or moreelectric components, and (ii) the magnetometer is located at least about3 cm away from the one or more electrical components; or (3) (i) the oneor more electrical component adapted to control operation of the UAV,and/or one or more rotor blades of said UAV; (ii) a magnetometer locatedat least 3 cm away and at most 0.5 m away from the one or moreelectrical components.

According to another aspect of the present invention, a method ofassembling an unmanned aerial vehicle (UAV) is provided. The methodcomprises following instructions provided in a kit comprising amagnetometer to incorporate said magnetometer into said UAV, therebyassembling said UAV, wherein said UAV when assembled is characterized inthat it comprises (1) (i) a housing comprising an outer surface and aninner surface that forms a cavity, disposed inside the cavity, the oneor more electric components, and (ii) the magnetometer is locatedoutside the housing; or (2) (i) a housing comprising an outer surfaceand an inner surface that forms a cavity, disposed inside the cavity,the one or more electric components, and (ii) the magnetometer islocated at least 3 cm away from the one or more electrical component; or(3) (i) the one or more electrical components adapted to controloperation of the UAV, and/or one or more rotor blades of said UAV; (ii)a magnetometer located at least 3 cm away and at most 0.5 m away fromthe one or more electrical components.

In some embodiments, the step of following instructions comprisesconnecting one or more rotor blades to the one or more electricalcomponents, and said step further comprising placing said magnetometerat a position on said UAV where said magnetometer does not experiencesignificant electromagnetic interference from said one or moreelectrical components.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 illustrates a multi-rotor unmanned aerial vehicle (UAV) withoutthe rotor blades, in accordance with an embodiment.

FIG. 2 illustrates a top view of the multi-rotor UAV of FIG. 1 withoutthe top portion of the housing to show the interior components, inaccordance with an embodiment.

FIG. 3 illustrates another view of the multi-rotor UAV of FIG. 1, inaccordance with an embodiment.

FIG. 4 illustrates support members of a multi-rotor UAV, in accordancewith an embodiment.

FIG. 5 illustrates a UAV with an extension member for attaching asensor, in accordance with an embodiment.

FIGS. 6a-c illustrate UAVs with extension members for attaching sensors,in accordance with some embodiments.

FIGS. 7a-c illustrate example UAVs where a sensor is located on an inneror outer surface of the body of the UAVs, in accordance with someembodiments.

FIGS. 8a-b illustrate more examples where a sensor is located on aninner or outer surface of the body of the UAVs, in accordance with someembodiments.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides methods and apparatus for improvingreliability unmanned aerial vehicles (UAVs). According to an aspect ofthe present invention, interference experienced by certain onboardsensors is reduced. Such interference can be caused by onboardelectrical components. The interference can include electromagneticinterference, magnetic interference, and the like. The onboard sensorswhich operation is susceptible or sensitive to such interference mayinclude sensors adapted to measure magnetic fields such asmagnetometers, compass, and the like. To reduce the interferenceexperienced by such “interference-susceptible” sensors, theinterference-generating electrical components can be positioned inside acavity of a UAV formed by the inner surface of the body of the UAV. Theinterference-susceptible sensor or sensors can be positioned outside thecavity. In some embodiments, the sensors can be located on an extensionmember of the UAV. The extension member can include a support member ofthe UAV, such as a landing stand. In some other embodiments, the sensorscan be located directly an outer or inner surface of the UAV body butseparately from the electrical components. Advantageously, theseparation of the interference-generating electrical components and theinterference-susceptible sensors reduces the interference experienced bythe sensors, thereby improving the reliability of the sensors and theUAV.

According to another aspect of the present invention, the reliability ofthe UAV can be further improved by reducing user-causedmis-configuration or mis-assembly of components. Some or all electricalcomponents can be pre-configured, pre-connected or otherwisepre-installed by a manufacturer of the UAV. As such, little or no userassembly or configuration is required for the UAVs to function properly.In addition, since the components are pre-configured by experiencedworkers, the likelihood of mis-configuration is further reduced. In someembodiments, one or more electric components are pre-configured by amanufacturer of the UAV to form an electrical unit necessary andsufficient for controlling operation of the UAV.

In various embodiments, the UAVs described herein may include UAVs ofvarious types, sizes, shapes, and configurations. For example, the UAVsmay include multi-rotor aircrafts such as helicopters, quadcopters,hexacopters, octocopters, and the like. Furthermore, the UAVs describedherein may be used in a wide variety of applications including but notlimited to remote sensing, aerial surveillance, oil, gas and mineralexploration and production, transportation, scientific research, aerialphotography or videography, mapping, disaster reporting, search andrescue, mapping, power line patrol, weather reporting and/or prediction,traffic detection and reporting.

In various embodiments, a UAV may be autonomously-controlled by anonboard controller or processor, remotely-controlled by a remote device(e.g., a ground station or a hand-held remote control device), orjointly controlled by both. In some embodiments, the UAV may beconfigured to carry a payload device such as a camera or a video cameravia a carrier. The payload device may be used to capture images ofsurrounding environment, collect samples, or perform other tasks.

As used herein, the terms “upper,” “lower,” “vertical,” “horizontal” andother similar position-indicating terms are used with reference to theUAV in its normal operational mode, and should not be consideredlimiting. Throughout the description, a quadcopter (a helicopter withfour rotors) is used as a UAV for illustrative purposes only. It isappreciated that the techniques described herein can be used for othertypes of UAVs such as a hexacopter or an octocopter.

As used herein, the term “body” is used interchangeably with the term“housing.”

As used herein, the term “electrical component” refers to any componentthat provides, uses or transmits electricity.

FIG. 1 illustrates a multi-rotor unmanned aerial vehicle (UAV) withoutthe rotor blades, in accordance with an embodiment. As illustrated, theUAV comprises a hollow body portion 10 that comprises an outer surfaceand an inner surface. The inner surface of the body portion encloses acavity (shown as 13 in FIG. 2) inside the body portion. As will bediscussed in more detail in connection with FIG. 2, one or moreelectrical components adapted to control various aspects of theoperation of the UAV may be disposed inside the cavity. Such electricalcomponents can include an energy source (e.g., battery), flight controlor navigation module, GPS module (e.g., GPS receivers or transceivers),inertial measurement unit (IMU) module, communication module (e.g.,wireless transceiver), electronic speed control (ESC) module adapted tocontrol an actuator (e.g., electric motor), actuator(s) such as anelectric motor used to actuate a rotor blade or rotor wing of the UAV,electrical wirings and connectors, and the like. In some embodiments,some of the electrical components may be located on an integratedelectrical unit such as a circuit board or module. One or moreelectrical units may be positioned inside the cavity. When in use, theelectrical components discussed herein may cause interference (e.g.,electromagnetic interference) to other components (e.g., magnetometer)of the UAV. In some embodiments, the interference may be caused byferrous material or static sources of magnetism. For example, theelectrical components may comprise magnets that generate magneticfields, thereby causing magnetic interference.

As illustrated by FIG. 1, the body portion 10 of the UAV comprises acentral housing member 11 and one or more branch housing members 12. Theinner surface of the central housing member can form a central cavity(shown as 113 in FIG. 2). Each of the branch housing members 12, in theshape of a hollow arm or any other suitable shape, can form a branchcavity (shown as 123 in FIG. 2). When the central housing member isconnected to the one or more branch housing members, the central cavityand the one or more branch cavities can collectively form one unifiedcavity (shown as 13 in FIG. 2).

The branch housing members 12 can be connected to the central housingmember 11 in an “X” or star shaped arrangement. Specifically, thecentral housing member 11 can be located at the center of the X or starshaped arrangement whereas the branch housing members 12 can bedistributed around the central housing member 11, in a symmetric orasymmetric fashion. In some embodiments, such a star-shaped arrangementcan facilitate efficient electrical connection between electricalcomponents disposed within the cavity of the housing, such as between acentrally located flight control module and the individual ESC moduleslocated in respective branch cavities. Or between a centrally locatedenergy source (e.g., battery) and actuators (e.g., electric motors) usedto drive the rotors of a multi-rotor UAV. In other embodiments, thehousing and/or the cavity inside the housing of the UAV may have a shapeother than the star shape described herein. For example, the housingand/or the cavity inside the housing can form a substantially spherical,elliptical, or cylindrical shape or any other shape.

In a typical embodiment, the number of branch housing members 12 isequal to the number of rotors or actuator assemblies of the UAV. Anactuator assembly (shown as 2 in FIG. 2) can include a rotor wing orrotor blade (shown as 21 in FIG. 2) and an actuator (shown as 22 in FIG.2) that is used to actuate the rotor blade. For example, a four-rotorquadcopter such as illustrated in FIG. 1 may have four branch housingmembers 12, each corresponding to one of the four rotors or actuatorassemblies. In the illustrated embodiment, the UAV has four branches,each corresponding to one actuator assembly 2. That is, the UAV has fouractuator assemblies 2. In various embodiments, the number of thebranches and/or the arrangement thereof may be different from thoseillustrated herein. For example, in some embodiments, there may be moreor less branch housing members and/or rotors or actuator assemblies thanillustrated here. For example, a 6-rotor UAV may have six rotors oractuator assemblies and six corresponding branch housing members. A8-rotor UAV may have eight rotors or actuator assemblies and eightcorresponding housing members. In alternative embodiments, the number ofbranch housing members may not correspond to the number of rotors oractuator assemblies of the UAV. For example, there may be more or lessbranch housing members than actuator assemblies. In various embodiments,the numbers of branches, actuator assemblies, and actuators can beadjusted according requirements of actual circumstances. To ensurestability of the UAV during operation, a typical multi-rotor UAV has noless than three rotors.

In some embodiments, the branch housing members 12 can be removablycoupled to the central housing member 11. For example, each branchhousing member 12 can be connected to and/or disconnected from thecentral housing member 11 by rotating the branch housing member 12 as awhole. In some embodiments, the branch housing members 12 may befoldable relative to the central housing member 11, for example, tofacilitate storage and/or transportation of the UAV. In suchembodiments, the branch housing members 12 can be expanded from thefolded position and/or reconnected to the central housing member inorder to put the UAV back to use.

In some embodiments, the central housing member 11 can include an uppercentral housing member 111 and a corresponding lower central housingmember 112 that collectively form the central cavity (shown as 113 inFIG. 2). Each of the branch housing members 12 can include an upperbranch housing member 121 and a corresponding lower branch housingmember 122 that collectively form the branch cavity (shown as 123 inFIG. 2). The upper branch housing members 121 of the branch housingmembers 12 may provide a mounting or positioning structure 120 such as aslot or opening for installing the actuator 22 of the actuator assembly(shown as 2 in FIG. 2).

In some embodiments, the upper branch housing members 121 and the uppercentral housing member 111 forms an upper body portion 15 and the lowerbranch housing members 122 and the lower central housing member 112forms the lower body portion (shown as 16 in FIG. 3). The body portion10 can be considered the combination of the upper body portion 15 andthe lower body portion 16. In some embodiments, the upper body portion15 and the lower body portion 15 may be removably coupled to form thebody portion 10. For example, during assembly of the body portion 10,the upper body portion and the lower body portion may be removablycoupled via fasteners such as screw, bolt, buckle, clamp, clasp, latch,hook, nail, pin, strap, cable, or the like. Such removable coupling canbe used to facilitate maintenance of the UAV. When maintenance isrequired, the upper body portion can be decoupled from the lower bodyportion to allow direct observation and maintenance of interiorcomponents of the body portion. In another embodiment, the upper bodyportion and the lower body portion may be welded or otherwisepermanently held together.

In various embodiments, any individual or combination of the componentsthat form the housing of the UAV can be manufactured using any suitabletechnique such as injection molding, additive manufacturing (3-Dprinting) techniques, or the like. For example, each of the uppercentral housing member, lower central housing member, upper branchhousing member and lower branch housing member can be manufacturedindividually and welded, fastened or otherwise combined to form theoverall housing. As another example, one or more upper branch housingmembers and the upper central housing member can be integrallymanufactured as one piece (i.e., forming the upper body portion);whereas one or more lower branch housing members and the lower centralhousing member can be integrally manufactured as another whole piece(i.e., forming the lower body portion). Then, the two integrallymanufactured pieces can be combined (via welding, fastener, etc.) toform the body portion of the UAV. As yet another example, the uppercentral housing member and the lower central housing member can beintegrally manufactured as one piece (i.e., forming the central housingmember); whereas for each of the branch housing members, the upperbranch housing member and the lower branch housing member can beintegrally manufactured as one piece (i.e., forming a branch housingmember). The central housing member and the branch housing members canthen be combined via welding, fastener, or the like. As yet anotherexample, the entire housing of the UAV can be integrally manufactured,for example, using injection molding or additive manufacturingtechniques.

As illustrated in FIG. 1, the UAV can optionally include one or moresupport members 4 that are attached or attachable to the body portion10. The support members 4 may be used to support in whole or in part theweight of the UAV when the UAV is not airborne. An example of a supportmember can include a landing stand provided to facilitate the landing ofthe UAV. As discussed herein, such a support member can also be used tosupport a sensor that is susceptible to the interference of theelectrical components of the UAV.

In some embodiments, the UAV includes one or more receiving structuresto accommodate some or all of the components of the UAV, such as some ofthe electrical components discussed herein. Such receiving structuresmay be coupled to the housing and may be an integral part of thehousing. The receiving structures may be positioned on the outer surfaceof the body portion or inside the cavity. As an example, a receivingstructure may be formed by the structure of the inner or outer surfaceof the body portion. In an embodiment, the receiving structure may forman addition receiving cavity besides the main cavity. In anotherembodiment, the receiving structure may be formed by interior structureson the inner surface of the main cavity. In an embodiment, the receivingstructures are all located inside the cavity. In another embodiment,some of the receiving structures are located outside cavity. Thereceiving structures may include slots, grids, housing, or other similarstructures to accommodate various components of the UAV. For example,the receiving structure may include a slot on the interior surface ofthe cavity formed by the body of the UAV that can be used to accommodatea circuit module, battery, ESC module or the like. In some embodiments,the UAV may not include any additional receiving structures other thanthe cavity formed by the housing of the UAV. In some other embodiments,some or all of the electrical components may be directly attached orcoupled to the UAV without the use of receiving structures.

The body portion and/or a receiving structure can include an opening forplacing and/or retrieving components thereto or therefrom. For example,such an opening may allow users to retrieve the battery from the cavityof the body portion or the receiving structure for recharge and forputting the battery back after the recharge. The opening may optionallyhave a corresponding flap or cover member that is hingedly coupled tothe body portion. The cover may be closed, such as by a clasp, buckle,strap, or the like, to secure the components located therein.

FIG. 2 illustrates a top view of the multi-rotor UAV of FIG. 1 withoutthe top portion of the housing to show the interior components, inaccordance with an embodiment. As discussed above, to avoid or reduceinterference with the interference-susceptible orinterference-susceptible sensors such as magnetometers (e.g., compass),one or more interference-generating electrical components of the UAV canbe located separately from the interference-susceptible sensors. In anembodiment, the electrical components are disposed inside the cavity 13formed by the inner surface of the housing of the UAV as discussed inconnection with FIG. 1 while the sensor is located outside the housing.Additionally, housing can provide protection to the electricalcomponents and increase the strength and rigidity of the UAV, making itwell-adapted to transportation and storage. In another embodiment, thesensor is also located inside the housing but separately from theelectrical components.

In various embodiments, the one or more electrical components may beadapted to control various aspects of the operation of the UAV. Suchelectrical components can include an energy source (e.g., battery),flight control or navigation module, GPS module (e.g., GPS receivers ortransceivers), inertial measurement unit (IMU) module, communicationmodule (e.g., wireless transceiver), electronic speed control (ESC)module adapted to control an actuator (e.g., electric motor), actuatorsuch as an electric motor that is used to actuate a rotor blade or rotorwing of the UAV, connecting members configured to electrically connectthe electrical components (such as electrical wirings and connectors),and the like. In various embodiments, some or all of the electricalcomponents of the UAV may be located inside the housing.

In some embodiments, some of the electrical components discussed abovemay be located on one or more circuit modules 3. Each circuit module caninclude one or more electrical components. For example, as shown in FIG.2, the circuit module 3 can include the main flight control module 33that includes one or more processors (such as implemented by afield-programmable gate array (FPGA)) for controlling key operations ofthe UAV. As another example, the same or a different circuit module canalso include an IMU module for measuring the UAV's velocity, orientationand/or gravitational forces. The IMU module can include one or moreaccelerometers and/or gyroscopes. As another example, the same or adifferent circuit module can also include a communication module 31 forremotely communicating with a remote control device. For example, thecommunication module can include a wireless (e.g., radio) transceiver.The communication module 31 can be provided with button or buttons 311and corresponding indicator light 312 that is spaced apart from the codebuttons. The buttons and the indicator light may be used for facilitatecommunication between the UAV and a remote control device. For example,the buttons may be used to adjust the frequency channel used by the UAVand the indicator light can be used to indicate the success and/orfailure of the establishment of a communication channel between the UAVand the remote control device.

The flight control module 33 is typically a key component or “brain” ofan UAV. For example, the flight control module 33 can be configured toestimate the current velocity, orientation and/or position of the UAVbased on data obtained from visual sensors (e.g., cameras), IMU, GPSreceiver and/or other sensors, perform path planning, provide controlsignals to actuators to implement navigational control, and the like. Asanother example, the flight control module can be configured to issuecontrol signals to adjust the state of the UAV based on remotelyreceived control signals.

In some embodiments, the electrical components located inside the cavitycan include a GPS receiver. Traditionally, a GPS receiver is typicallyco-located with a magnetometer. However, when the GPS receiver andmagnetometer are located close to the other electrical components, theoperation of the magnetometer can be affected by the interference fromthe other electrical components. In some embodiments, operation of themagnetometer can also be affected by interference from the GPS receiver.Therefore, in a preferred embodiment of the present invention, the GPSreceiver is separated from the magnetometer so that the GPS receiver islocated inside the housing the UAV and the magnetometer is locatedoutside the housing. In alternative embodiments, the GPS receiver andthe magnetometer may both be located inside or outside the housing butthere is a minimum distance between the GPS receiver and themagnetometer. In an embodiment, such a minimum distance is about3centimeters (3 cm). In other embodiments, the minimum distance can beless or more than 3 cm.

In some embodiments, the electrical components located inside the cavitycan include one or more electronic speed control (ESC) modules 34. AnESC module can be adapted to control the operation of an actuator 22.The actuator 22 can be part of an actuator assembly 2 and configured toactuator a rotor blade or wing 21 of the UAV. In some embodiments, theESC module can be electrically connected to the flight control module 33on the one hand, and an actuator 22 on the other hand. The flightcontrol module 33 can provide control signals for the ESC module 34,which in turn provides actuator signals to the electrically connectedactuator 22 so as to actuate the corresponding rotor blade 21. In someembodiments, feedback signals can also be provided by the actuator 22and/or the ESC module 34 to the flight control module 33. In a typicalembodiment, the number of ESC modules is equal to the number of rotoractuators of the UAV. For example, a 4-rotor UAV has four ESC modules.In an alternative embodiment, the number of ESC modules may be different(more or less) than the number of rotor actuators. In some embodiments,the ESC modules may be optional. In some embodiments, instead of or inaddition to the ESC module, other types of actuator control module canbe provided to control the operation of the actuators.

In some embodiments, the UAV also includes one or more connectingmembers for electrically coupling or connecting the various electricalcomponents of the UAV. Such connecting members can include electricalwires, cables, and the like that are used for transmitting power, dataor control signals between the components. For example, the connectingmembers can be used to electrically connect 1) an energy source and anactuator assembly; 2) a circuit module and an ESC module; 3) an ESCmodule and an actuator; 4) a communication module and a circuit module,or the like. In some embodiments, the connecting members have pluggableconnectors at the distal portions to facilitate plugging and unpluggingof the connecting members with respect to the electrical components.

As discussed above in connection with FIG. 1, the cavity of the UAV canbe of any suitable shape. In various embodiments, the locations of thevarious electrical components can be determined based on the design andlayout of the UAV. In some embodiments, the cavity of the UAV includes acentral cavity 113 and multiple branch cavities 123, each correspondingto a separate actuator assembly 2. In some embodiments, some of theelectrical components can be located inside the central cavity whereasothers may be located in the branch cavities. In other embodiments, allof the electrical components may be located in one portion (e.g.,central cavity or branch cavity) of the cavity. In an embodiment, thekey control components such as the flight control module and the energysource (e.g., battery) can be located in the central cavity whereascontrolled components such as the ESC modules and the actuatorassemblies are located in respective branch cavities. Such anarrangement provides efficient layout of electrical connection betweenthe centrally-located components and components for which the centrallylocated components provide power and/or control signals and canfacilitate space-optimization and miniaturization of the UAV.

In an embodiment, the ESC module 34 can be positioned inside a branchhousing member and below the actuator. For example, the ESC module 34can be located in the lower branch housing members 122 and within thebranch cavity 123. The placement of the ESC module 34 inside the branchhousing members 123 can facilitate the electric coupling between the ESCmodule 34 and the actuator 22. In alternative embodiments, at least oneof the ESC modules 34 can be located inside the central cavity insteadof a branch cavity.

In some embodiments, the actuator assembly 2 controlled by the ESCmodule can be located at least partially inside a branch cavity. Theactuator assembly 2 can include actuator 22 that is connected to thebranch housing members 12 and rotor blade 21 that is coupled to theactuator 22. As illustrated in FIG. 1, a portion of the actuator 22 canextend at least partially from the cavity to rotatably couple with arotor blade or rotor wing (shown as 21 in FIG. 2). For example, theactuator can have a shaft 221 that is rotatably attachable to the rotorblade 21. The actuator 22 can includes electric motor, mechanicalactuator, hydraulic actuator, pneumatic actuator, and the like. Electricmotors can include magnetic, electrostatic, or piezoelectric motors. Forexample, in an embodiment, the actuator includes a brushless DC electricmotor. The actuator assembly 2 can be fixedly or removably coupled tothe branch housing members 12. In some embodiments, the UAV has at leastthree actuator assemblies to ensure stability of the UAV duringoperation.

In some embodiments, some or all of the electrical components discussedabove are pre-configured, pre-assembled or pre-connected by amanufacturer of the UAV. In such embodiments, no or very little userassembly and/or calibrate may be required for the UAV to operate, makingthe UAV “ready-to-fly” out-of-the-box. Such pre-configuration ofcomponents not only enhances the user experience by lowering thetechnical expertise required, but also reduces the errors or accidentscaused by user mis-configuration. In some embodiments, suchpre-configured or pre-assembled components can include the flightcontrol module, GPS receiver, ESC module, or any of the electricalcomponents discussed herein, or any combination thereof. In someembodiments, one or more electrical components may be pre-configured,pre-connected or pre-assembled as an electrical unit (e.g., a circuitmodule). The electrical unit may be necessary and sufficient forcontrolling operation of the UAV. In some embodiments, no additionaluser configuration is required for the pre-configured components tooperate properly out-of-the-box. In other embodiments, some amount ofuser configuration or assembly may be required.

In an embodiment, at least two of the electrical components may bepre-connected by a manufacturer of the UAV to reduce user assembly thatis required before the UAV can be used. For example, the electricalconnection between the circuit module and the ESC module may bepre-connected by the manufacturer so that the user need not connect thetwo modules after purchasing the UAV. Such pre-configuration,pre-connection or pre-assembly can also simplify the design of the UAV.For example, not all of the connecting members may need to providepluggable connectors: some of the connecting members can bepre-connected to components, by the manufacturer, by welding, therebyimproving the reliability of such connections. Even where pluggableconnectors are used, such connections can be performed properly bytrained professionals such as mechanics during factory assembly, therebyreducing the risk of loose and/or incorrect connections and furtherimproving the reliability of the UAV.

FIG. 3 illustrates another view of the multi-rotor UAV of FIGS. 1-2, inaccordance with an embodiment. The illustrated UAV shows the placementof an interference-susceptible sensor 7 (e.g., a magnetometer) outsidethe body portion of the UAV to reduce interference experienced by thesensor that is caused by one or more electrical components of the UAVsuch as those discussed in connection with FIG. 2.

In various embodiments, the interference-susceptible sensor 7 includes asensor which operation is susceptible to interference caused by theonboard electrical components. The interference may includeelectromagnetic or magnetic interference. The interference may be causedby the electric current or magnets in the electric components. Theinterference-susceptible sensor 7 can include a magnetometer.Magnetometers may include scalar and/or vector magnetometers. In anembodiment, the magnetometer includes a compass. In a preferredembodiment, the interference-susceptible sensor 7 includes magnetometerbut not a GPS receiver. In an alternative embodiment, theinterference-susceptible sensor 7 includes a GPS receiver and amagnetometer. It is appreciated that while one interference-susceptiblesensor is used for illustrative purpose, more than oneinterference-susceptible sensor may be carried by the UAV and theinterference-reduction techniques described herein may be used for anyor all of such interference-susceptible sensors.

In some embodiments, to reduce interference from electrical componentsof the UAV and to improve the reliability of the UAV, theinterference-susceptible sensors are positioned at some distance fromthe electrical components that tend to generate such interference. Forexample, all electrical components that generate interference to theinterference-susceptible sensor can be placed away from the sensor. Inother embodiments, only some of the interference-generating electricalcomponents are located away from the sensor. Some or all of theinterference-generating electrical components can be placed at leastabout 3, 4, 5, 6, 7, 8, 9, 10 or more centimeters away from the sensor.In some instances, some or all of interference-generating electricalcomponents are placed within a distance of about 3 centimeters fromabout 0.5 meters.

In some embodiments, such as discussed in connection with FIGS. 1-2, theinterference-generating electrical components are located inside thecavity of the body portion of the UAV whereas theinterference-susceptible sensor is located outside the cavity of thebody. In some embodiments, the sensor is located on an extension memberextending from the housing and away from the cavity therein. In someembodiment, the extension member may include a support member that isadapted to support, in whole or in part, weight of the UAV when the UAVis not airborne. For example, the support member may include a landingstand 4 such as illustrated in FIG. 3. In an alternative embodiment, theUAV does not have a stand or similar structure such as that when the UAVis positioned on a given surface, the outer surface of the lower centralhousing directly contact the surface. In some embodiments, the sensormay be located outside the cavity and on the outer surface of thehousing. More detailed discussion of some embodiments is provided inconnection with FIGS. 5-8.

In some embodiments, the minimum distance between the sensor and theelectrical components is set to be no more than a predefined thresholdvalue regardless of the locations of the sensor or the electricalcomponents. For example, in an embodiment, the electrical components andthe sensor may be both located inside the housing or both outside thehousing but the minimum distance is at least about 3 cm. In someembodiments, the minimal distance can be less than 3 cm. As used herein,the minimum distance between a sensor and a plurality of electricalcomponents is the shortest distance between the sensor and any of theplurality of electrical components. The maximum distance is similarlydefined. For example, if a flight control module, an ESC module and anactuator are located 4 cm, 7 cm and 8 cm from a magnetometer, theminimum distance between the magnetometer and this group of electricalcomponents is 4 cm and the maximum distance is 8 cm. In someembodiments, the maximum distance between the interference-susceptiblesensor and any interference-generating electrical component is also setto be no more than a predefined threshold value, for example, 0.5 meter(0.5 m). In other embodiments, the maximum distance can be more than 0.5m. In various embodiments, the threshold value the minimum and/ormaximum distance may be determined based at least in part on the shapeand/or dimensions of the UAV, the characteristics of theinterference-generating electrical components and the characteristics ofthe interference-susceptible sensor.

In some embodiments, the UAV may not have a housing such as illustratedin FIGS. 1-3 at all. In such embodiments, the separation of theinterference-generating electrical components andinterference-susceptible sensor may be sufficient to reduce theinterference experienced by the interference-susceptible sensor. Forexample, in an embodiment, distance between the interference-susceptiblesensor and any interference-generating electrical component is no lessthan 3 cm and no more than 0.5 m.

In various embodiments, additional interference reduction methods may beused in conjunction with the techniques described herein. Such methodsmay include the use of capacitors, filters, shielding, and the like. Forexample, in an embodiment, the inner surface and/or outer surface of thebody portion may be made of a conductive shielding material to furtherreduce the interference caused by the electrical components.

In some embodiments, such as illustrated in FIG. 3, the UAV may carry apayload device 6 (e.g., camera or video camera) via a carrier 5. Thecarrier 5 may be coupled to the UAV and configured to be coupled to thepayload device 6. In various embodiments, the operation of the payloaddevice 6 and/or the carrier 5 can be controlled by an onboard controlmodule (e.g., circuit module), a remote control device, or a combinationof both.

In some embodiment, the central housing or the branch housing may beprovided with an indicator light source (not shown). In an embodiment,the light source may be positioned at an opening or window on the branchhousing such as towards the lower portion of the UAV away from therotors). The opening or window may be covered by a window cover that ismade of a transparent or semi-transparent material so as to allowpassage of at least some of the light from the indicator light source.In a preferred embodiment, the indicator light source includes alight-emitting diode (LED) light, which provides high brightness, lowpower consumption, long-lasting life of use, and ease of transportation.In other alternative embodiments, the indicator light source, window andwindow cover can be located on the central housing.

FIG. 4 illustrates a pair of landing stands that may be used forattaching an interference-susceptible sensor, in accordance with anembodiment. The landing stands 4 may be similar to those illustrated inFIG. 3. As discussed above, the landing stand may be adapted to support,in whole or in part, the weight of the UAV when the UAV is not airborne.In an embodiment, the UAV has two similarly structured stands that arecoupled to the body of the UAV and spaced apart at a suitable distance.In various embodiments, the UAV can include one, two, three or morestands. The stands can be attached the bottom of the housing (on theopposite side of the rotors) in any suitable configuration so as tosupport the weight of the body portion. The stands may also provideprotection for any payload device (such as a camera or video camera)that may be located between the stands. Advantageously, using anexisting structure of the UAV, such as a landing stand, requires noadditional structure to be added to the UAV for increasing the distancebetween the interference-susceptible sensor and theinterference-generating electrical components of the UAV, therebyreducing the weight and cost of the UAV while improving the aesthetic ofthe UAV.

In some embodiments, such as illustrated, the UAV may include a firststand 41 and a second stand 42. The interference-susceptible sensor maybe located on the first stand 41 or the second stand 42. The descriptionof the first stand 41 is provided in the following discuss as the firstand second stands can have similar structures. The first stand 41 canhave two substantially vertical support portions 411 which are connectedby a substantially horizontal connecting portion 412. When in use, aninterference-susceptible sensor 7 can be coupled to one of the supportportions 411 and away from the source of the interference. For example,the sensor 7 can be disposed toward an end of the support portion andaway from the source(s) of interference. In other embodiments, thesensor 7 may be located on a different portion of the first stand 41than illustrated here. In some embodiments, each support portion 411 canhave an attachment interface 413 which may be used to attach the supportportion and hence the stand to a UAV. The attachment interface 413 caninclude one or more openings 414. Such openings may be used for allowingand securing the passage of wires connecting theinterference-susceptible sensor and other components of the UAV such asthe circuit module.

FIGS. 5-8 illustrate example configurations of interference-susceptiblesensor and interference-generating electrical components, according tosome embodiments.

As discussed herein, in some embodiments, the interference-generatingelectrical components can be located inside the cavity of a body of UAVand the interference-susceptible sensor can be located outside on anextension member that extends away from the cavity. FIGS. 5-6 illustratesome of such embodiments. Referring to FIG. 5, the body 502 of the UAVmay enclose therein one or more interference-generating electricalcomponents (not shown). An extension member 504 can be attached, at oneend, to the outer surface of the body portion 502 of the UAV. Aninterference-susceptible sensor 506 can be coupled to a portion of theextension member 504 that is closer to the other end of the extensionmember 504 that is away from the cavity such that there is a distancebetween the interference-susceptible sensor 506 and theinterference-generating electrical components. The sensor 506 may becoupled (removably or permanently) to the extension member 504 via afastener, glue, welding or any other suitable methods. In variousembodiments, the extension member 504 can include a pole, hook,platform, slot, or any other suitable structure. It is appreciated thatin some embodiments, the interference-susceptible sensor can be operablyconnected to the interference-generating electrical components such asvia a wired or wirelss link. Such a link is not necessarily depicted inFIGS. 5-8. In an embodiment, the extension member may include a hollowcavity that allows for the passage of the wire(s) connecting the sensorand other component(s) of the UAV (not shown).

FIG. 6a illustrates a side view of the UAV shown in FIG. 5. Asillustrated, the inner surface of the body portion 602 of the UAV formsa cavity. Interference-generating electrical components 608, 610, and612 may be disposed inside the cavity. The interference-generatingelectrical components can also include one or more connecting members614 that electrically connect some of the other electrical components.The interference-generating electrical components can include any ofthose described herein such as a circuit module, flight control module,GPS receiver, energy source, ESC module, actuator or actuator assembly,and the like. It is appreciated that in various embodiments, more orless interference-generating electrical components than illustrated maybe provided. An extension member 604 is attached to the upper outersurface of the body of the UAV and extends away from the cavity. Aninterference-susceptible sensor 606 may be coupled (removably orpermanently) to the extension member 604. In a typical embodiment, theinterference-susceptible sensor 606 is located on a portion of theextension member 604 that is away from the cavity, such as towards adistal end that is not attached to the outer surface of the body of theUAV.

The illustrated example shows the extension member attached to the upperportion of the UAV body. In other embodiments, the extension member canbe attached to the outer surface at other locations. FIGS. 6b-cillustrate some of such embodiments. In some embodiments, such asillustrated by FIG. 6b , the extension member 604 may be attached to alower portion of the body and extends away from the cavity. In someother embodiments, such as illustrated by FIG. 6c , the extension member604 may attached to a side portion of the body and extends away from thecavity. In other embodiments, the extension member may be attached toother locations not illustrated herein. In some embodiments, more thanone interference-susceptible sensor may be provided for one UAV. In suchembodiments, the sensors may be located on one or more extension memberssuch as illustrated here. In some embodiments, multiple extensionmembers may be attached to different portions of the outer surface ofthe UAV body.

In some embodiments, the extension member may be attached to the innersurface of the body portion. In such an embodiment, the extension membermay or may not be also attached to the outer surface of the bodyportion. For example, in an embodiment, the extension member may passthrough and be in contact with both the inner surface and the outersurface of the body portion. In another embodiment, the extension membermay be attached to only the inner surface of the body portion andextends away from the cavity without being in contact with the outersurface (e.g., by passing through without touching an opening on thebody portion of the UAV).

In some embodiments, instead of or in addition to using extensionmember, the interference-susceptible sensor may be attached directly tothe inner or outer surface of the body of the UAV and away from theinterference-generating electrical components. FIGS. 7a-c illustrate aside view of a UAV along a plane that is substantially orthogonal to theplane formed by the rotors of the UAV, in accordance with someembodiments. In these figures, the body 702, interference-susceptiblesensor 706 and the interference-generating electrical components 708,710, 712 and 714 may be similar to the body 602,interference-susceptible sensor 606 and the electrical components 608,610, 612 and 614 discussed in connection with FIG. 6. However, in FIGS.7a-c , the interference-susceptible sensor 706 is located directly on aninner or outer surface of the UAV body without the use of an extensionmember. In some embodiments, such as illustrated by FIG. 7a ,interference-susceptible sensor 706 may be located directly on an innersurface that is on the same side as the rotor blades (or an upper innersurface of cavity) and away from the various interference-generatingelectrical components. In some other embodiments, such as illustrated byFIG. 7b , interference-susceptible sensor 706 may be located directly onan outer surface outside the cavity that is on the same side as therotor blades (or an upper outer surface). In some other embodiments,such as illustrated by FIG. 7c , the interference-susceptible sensor 706may be located directly on an outer surface that is on opposite side asthe rotor blades (or a lower outer surface) and away from the electricalcomponents. In some other embodiments (not shown), theinterference-susceptible sensor may be located directly on an innersurface that is on the opposite side as the rotor blades (or a lowerinner surface) and away from the electrical components.

FIGS. 8a-b illustrate a top-down view of some other embodiments whereinthe interference-susceptible sensor is directly attached to an inner orouter surface of the UAV. However, unlike the embodiments shown in FIGS.7a-c , the illustrated views are along plane that is substantiallyparallel to the plane formed by the rotors of the UAV. As shown, thebody 802, interference-susceptible sensor 806 and theinterference-generating electrical components 808, 810, 812 and 814 maybe similar to the body 702, interference-susceptible sensor 706 and theelectrical components 708, 710, 712 and 714 discussed in connection withFIGS. 7a -c. In some embodiments, such as illustrated by FIG. 8a , thesensor 806 is located along a side inner surface of the body portion ofthe UAV. In some other embodiments, such as illustrated by FIG. 8b , thesensor 806 is located along a side outer surface of the body portion ofthe UAV.

In some embodiments, the sensor may be attached on the inner or outersurface of the body of the UAV by a fastener (e.g., strap, wire), glue,welding or the like. In some other embodiments, the sensor may be heldin place on such surfaces by receiving structures such as slots, gridsand the like. In some other embodiments, the sensor may be merely placedon such surfaces without the use of any fastener or receivingstructures. In some embodiments, more than one interference-susceptiblesensor may be attached to various locations of the body portion of theUAV with or without extension members. For example, in an embodiment,some of the sensors may be attached to the body portion via extensionmembers while others are directly attached to the inner or outer surfaceof the UAV body.

In various embodiments, the interference experienced by theinterference-susceptible sensor may be measured by field headingdeviation and/or the field strength of magnetic interference. Such levelof interference may be obtained by comparing the readings of the sensorwhen the electrical components are powered off and on, respectively. Thelevel of interference, that is, the difference between the on and offreadings, can vary when the location of the sensor is varied. Inparticular, when the distance between the sensor and the electricalcomponents increases, the level of interference can decrease. Forexample, the heading deviation caused by the interference and/or thestrength of the magnetic interference may be weakened. For example, whenthe sensor and the electrical components are located, respectively,outside and inside the body of the UAV, the heading deviationexperienced by the magnetometer may be less, by a certain thresholdvalue, than the heading deviation experienced by the magnetometer whenit is inside the body of the UAV. Such threshold value may be around 15degrees, 10 degrees, 5 degrees or the like. As another example, when thesensor and the electrical components are located, respectively, outsideand inside the body of the UAV, the field strength experienced by themagnetometer may be less, by a certain threshold value, than the fieldstrength experienced by the magnetometer when it is inside the body ofthe UAV. Such threshold value may be around 0.5 gauss, 0.3 gauss, 0.1gauss, or the like.

In various embodiments, the present invention may be applied to UAVs ofdifferent sizes, dimensions and/or configurations. For example, in anembodiment, the present invention can be applied to multi-rotor UAVswhere the distance between the shafts of opposing rotors does not exceeda certain threshold value. Such threshold value may be around 5 meters,4 meters, 3, meters, 2 meters, 1 meter, or the like. For instances, thevalues of the distance between shafts of opposing rotors may be 350millimeters, 450 millimeters, 800 millimeters, 900 millimeters and thelike.

In some embodiments, the UAV may be of a size and/or dimensionssufficient to accomodate a human occupant within or on the UAV.Alternatively, the UAV may be of size and/or dimensions smaller thanthat capable of having a human occupant within or on the UAV. In someinstances, the UAV may have a maximum dimension (e.g., length, width,height, diameter, diagonal) of no more than 5 m. For example, thedistance between shafts of opposing rotors may be no more than 5 m. Insome embodiments, the UAV may have a volume of less than 100 cm×100cm×100 cm. In some embodiments, the UAV may have a volume of less than50 cm×50 cm×30 cm. In some embodiments, the UAV may have a volume ofless than 5 cm×5 cm×3 cm. In some embodiments, the UAV may have afootprint (which may refer to the lateral cross-sectional areaencompassed by the UAV) less than about 32,000 cm², less than about20,000 cm², less than about10,000 cm², less than about1,000 cm², lessthan about 500 cm², less than about 100 cm² or even less. In someinstances, the UAV may weigh no more than1000 kg, no more than 500 kg,no more than100 kg , no more than10 kg, no more than 5 kg, no more than1kg, or no more than 0.5 kg. In some embodiments, a UAV may be smallrelative to the load (comprising payload device and/or carrier). In someexamples, a ratio of a UAV weight to a load weight may be greater than,less than, or equal to about 1:1. In some instances, a ratio of a UAVweight to a payload weight may be greater than, less than, or equal toabout 1:1. Where desired, the a ratio of a UAV weight to a load weightmay be 1:2, 1:3, 1:4, or even less. Conversely, the ratio of a UAVweight to a load weight can also be designed to 2:1, 3:1, 4:1, 5:1 oreven higher. Optionally, a ratio of a carrier weight to a payload weightmay be greater than, less than, or equal to about 1:1. Where desired,the ratio of carrier's weight to payload's weight may 1:2, 1:3, 1:4, oreven less. Conversely, the ratio of carrier's weight to payload's weightmay 2:1, 3:1, 4:1, 5:1, or even higher. In some embodiments, the UAV mayhave low energy consumption. For example, the UAV may use less than 2w/h. In some instances, the carrier may have low energy consumption. Forexample, the carrier may use less than 2 w/h.

In various embodiments, a kit for assembling an unmanned aerial vehiclemay be provided. In some embodiments, the kit comprises one or moreelectrical components adapted to control operation of the UAV, and/orone or more rotor motors of said UAV. The kit also comprisesinstructions comprising information for a user of said UAV to assemblethe above mentioned electrical components with a magnetometer. In anembodiment, a UAV assembled according to the instructions ischaracterized in that it comprises a housing comprising an outer surfaceand an inner surface that forms a cavity, disposed inside the cavity,the one or more electric components, and the magnetometer is locatedoutside the housing. In another embodiment, a UAV assembled according tothe instructions is characterized in that it comprises a housingcomprising an outer surface and an inner surface that forms a cavity,disposed inside the cavity, the one or more electric components, and themagnetometer is located at least about 3 cm away from the one or moreelectrical components. In another embodiment, a UAV assembled accordingto the instructions is characterized in that it comprises the one ormore electrical component adapted to control operation of the UAV,and/or one or more rotor blades of said UAV and a magnetometer locatedat least 3 cm away and at most 0.5 m away from the one or moreelectrical components.

In some embodiments, the kit for assembling the UAV may comprise amagnetometer; and instructions comprising information for a user of saidUAV to assemble said magnetometer with one or more electrical componentsadapted to control operation of the UAV. In an embodiment, a UAVassembled according to the instructions is characterized in that itcomprises a housing comprising an outer surface and an inner surfacethat forms a cavity, disposed inside the cavity, the one or moreelectric components, and the magnetometer is located outside thehousing. In another embodiment, a UAV assembled according to theinstructions is characterized in that it comprises a housing comprisingan outer surface and an inner surface that forms a cavity, disposedinside the cavity, the one or more electric component, and themagnetometer is located at least about 3 cm away from the one or moreelectrical component. In another embodiment, a UAV assembled accordingto the instructions is characterized in that it comprises the one ormore electrical component adapted to control operation of the UAV,and/or one or more rotor blades of said UAV and a magnetometer locatedat least about 3 cm away and at most 0.5 m away from the one or moreelectrical components.

In some embodiments, the kit for assembling the UAV may comprise ahousing comprising an outer surface and an inner surface that forms acavity, one or more pre-configured electrical components disposed insidethe cavity and adapted to control operation of the UAV, a magnetometer,operation of the magnetometer being susceptible to interference from theone or more electrical components, and instructions for assembling saidUAV. In an embodiment, when the UAV is assembled according to theinstructions, the assembled UAV is characterized in that themagnetometer is located outside the housing. In another embodiment, theassembled UAV is characterized in that the magnetometer is located atleast about 3 cm away from the one or more electrical component. Inanother embodiment, the assembled UAV is characterized in that themagnetometer is located at most 0.5 m away from the one or moreelectrical components.

In some embodiments, the kit for assembling a UAV may further comprisean extension member that is attachable to the outer surface of thecavity and the assembled UAV is further characterized in that theextension member is attached to the outer surface of the housing and themagnetometer is located on the extension member.

According to another aspect of the present invention, methods forassembling a UAV are provided. In some embodiments, the method ofassembling an unmanned aerial vehicle may comprise followinginstructions provided in a kit comprising one or more electricalcomponents adapted to control operation of the UAV, and/or one or morerotor blades of said UAV, thereby assembling said UAV. In an embodiment,said UAV when assembled is characterized in that it comprises a housingcomprising an outer surface and an inner surface that forms a cavity,disposed inside the cavity, the one or more electric components, and themagnetometer is located outside the housing. In another embodiment, saidUAV when assembled is characterized in that it comprises a housingcomprising an outer surface and an inner surface that forms a cavity,disposed inside the cavity, the one or more electric components, and themagnetometer is located at least about 3 cm away from the one or moreelectrical components. In another embodiment, said UAV when assembled ischaracterized in that it comprises the one or more electrical componentadapted to control operation of the UAV, and/or one or more rotor bladesof said UAV and a magnetometer located at least about 3 cm away and atmost 0.5 m away from the one or more electrical components.

In some embodiments, the method of assembling an unmanned aerial vehiclemay comprise following instructions provided in a kit comprising amagnetometer to incorporate said magnetometer into said UAV, therebyassembling said UAV. In an embodiment, said UAV when assembled ischaracterized in that it comprises a housing comprising an outer surfaceand an inner surface that forms a cavity, disposed inside the cavity,the one or more electric components, and the magnetometer is locatedoutside the housing. In another embodiment, said UAV when assembled ischaracterized in that it comprises a housing comprising an outer surfaceand an inner surface that forms a cavity, disposed inside the cavity,the one or more electric components, and the magnetometer is located atleast about 3 cm away from the one or more electrical component. Inanother embodiment, said UAV when assembled is characterized in that itcomprises the one or more electrical components adapted to controloperation of the UAV, and/or one or more rotor blades of said UAV and amagnetometer located at least about 3 cm away and at most 0.5 m awayfrom the one or more electrical components.

In some embodiments, the step of following instructions comprisesconnecting one or more rotor blades to the one or more electricalcomponents such that they are electrically coupled to each other. Insome embodiments, the said step further comprising placing saidmagnetometer at a position on said UAV where said magnetometer does notexperience significant electromagnetic interference from said one ormore electrical components.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the invention. It should be understoodthat various alternatives to the embodiments of the invention describedherein may be employed in practicing the invention. It is intended thatthe following claims define the scope of the invention and that methodsand structures within the scope of these claims and their equivalents becovered thereby.

1. (canceled)
 2. A multi-rotor unmanned aerial vehicle (UAV), comprising: a central body comprising an upper housing member and a lower housing member, the upper housing member and the lower housing member forming a central cavity configured to house at least one electrical component for controlling operation of the UAV; a branch housing member configured to extend from the central body, wherein the branch housing member comprises a branch cavity, and wherein the branch housing member is configured to be foldable relative to the central body to transform the UAV between a folded configuration and an expanded configuration; and an actuator assembly coupled to the branch housing member, wherein the actuator assembly comprises an actuator configured to effect movement of the UAV, wherein at least a portion of the branch housing member extends beneath the actuator.
 3. The UAV of claim 2, wherein the thrust of the actuator assembly is oriented in a vertical direction relative to the central body.
 4. The UAV of claim 2, wherein the branch housing member comprises a plurality of members which form the branch cavity.
 5. The UAV of claim 2, further comprising an electronic speed control (ESC) configured to be electrically coupled to the actuator assembly, wherein the ESC is disposed in the central cavity.
 6. The UAV of claim 2, further comprising an electronic speed control (ESC) configured to be electrically coupled to the actuator assembly, wherein the ESC is not disposed in the central cavity.
 7. The UAV of claim 2, further comprising a plurality of branch housing members.
 8. The UAV of claim 2, further comprising a magnetometer at a distance of at least 3 cm from the at least one electrical components.
 9. The UAV of claim 8, wherein the magnetometer is at a distance of no more than 0.5 m away from the at least one electrical components.
 10. The UAV of claim 8, wherein the magnetometer is secured to an extension member extending away from the central body.
 11. The UAV of claim 10, wherein the extension member is a landing stand configured to bear weight of the UAV when the UAV is not airborne.
 12. A multi-rotor unmanned aerial vehicle (UAV), comprising: a central body comprising an upper housing member and a lower housing member, the upper housing member and the lower housing member forming a central cavity configured to house at least one electrical components for controlling operation of the UAV; a plurality of branch housing members configured to extend from the central body, wherein each of the plurality of branch housing members comprises a branch cavity, and wherein the plurality of branch housing members is configured to be foldable relative to the central body to transform the UAV between a folded configuration and an expanded configuration; a plurality of actuator assemblies each coupled to one branch housing member of the plurality of branch housing members, wherein the plurality of actuator assemblies is configured to effect movement of the UAV; and a plurality of electronic speed control (ESC) modules each configured to be electrically coupled to one actuator assembly of the plurality of branch housing members to control actuation of the actuator assemblies, wherein each ESC module of the plurality of ESC modules are located within a respective branch cavity.
 13. The UAV of claim 12, wherein each ESC module of the plurality of ESC modules are operably coupled to a flight control module to permit two-way communication between the flight control module and each ESC module.
 14. The UAV of claim 12, wherein the central cavity comprises at least one interior structure formed therein configured to accommodate the at least one electrical components.
 15. The UAV of claim 14, wherein the at least one interior structure comprises slots, grids, or housings that accommodate the at least one electrical components.
 16. The UAV of claim 12, further comprising an energy source configured to provide electrical energy to the plurality of actuator assemblies, wherein the central body is configured to receive the energy source.
 17. The UAV of claim 16, wherein the energy source is within the central cavity.
 18. The UAV of claim 12, wherein each of the plurality of branch housing members comprise a plurality of members which form the branch cavity.
 19. The UAV of claim 12, further comprising a magnetometer at a distance of at least 3 cm from the electrical components.
 20. The UAV of claim 19, wherein the magnetometer is at a distance of no more than 0.5 m away from the one or more electrical components.
 21. The UAV of claim 19, wherein the magnetometer is secured to an extension member extending away from the central body. 